Building Reefs Out Of Junk May Hurt Fish, Biologist Says

MELBOURNE — For thousands of years people in the Orient have used bamboo and other native woods to make reefs that attract fish. Once the fish are in one spot, it's easy to haul in a great catch.

Westerners followed suit in the past several decades, but instead of using natural materials, their man-made reefs often were fashioned from old washing machines, water heaters and ships.

Now that scores of artificial reefs have been built off the United States, with a large number near Florida, scientists are beginning to question their long-term effects.

William Alevizon, a marine biologist at the Florida Institute of Technology in Melbourne, believes an experimental artificial reef project he is supervising will provide some answers.

''The Japanese are spending $60 million this year to design and build artificial reefs,'' he says. ''The American approach still is to throw waste materials in the water and wait for fish to appear.

''This carnival atmosphere of making a reef by sinking a Rolls-Royce or an airplane really bothers me . . . it's permanently changing the environment and that should be taken very seriously.''

Scientists already know why fish are attracted to solid objects in the sea. Reefs, whether natural or man-made, provide small enclosed areas where fish can hide, making them less vulnerable to predators.

''Algae and other organisms also grow on reefs and provide food for some species,'' Alevizon says.

But do reefs actually attract new fish to an area or simply concentrate the aquatic life already there?

What will decaying metal, rubber and other materials used to construct man- made reefs do to the ocean over time?

Do reefs mean a permanent change in fish populations or are the benefits fleeting?

Will reefs eventually lead to a decline in some species as they are over- fished from the sea?

Alevizon hopes to have the first scientific data on these questions by 1987, when the next International Conference on Artificial Reefs is held in Miami.

In his two-year project, clusters of reefs made from plastic PVC pipe and concrete blocks will be studied to determine how they change the native fish population. The reefs have been set up just off Big Pine Key in the Looe Key National Marine Sanctuary with a $90,000 grant from The Florida Sea Grant foundation and FIT.

Before Alevizon and two FIT graduate assistants began installing the 4-by- 8-foot reefs in December, they surveyed all the fish in the area. Now that the reefs are in place, the scientists will monitor the fish population every month to see how the size, number and type of fish change over time. A year from now, he will place one reef in the center of the cluster of reefs now there to see if fish from the community are drawn to the latest reefs or if new fish come there from outside.

Later this month, Alevizon will install three reefs in the main Living Seas exhibit at Walt Disney World's Epcot Center so people can see how reef communities work. Once they understand how fragile undersea life is, he hopes the public will be persuaded to think twice before more trash is dumped in the ocean to make good fishing grounds.

''As usual, people want immediate economic benefits and haven't stopped to worry about what's going to happen 50 years down the road,'' Alevizon says. ''That lack of foresight has been the cause of a lot of environmental disasters, which is why we're saying let's take a more cautious approach until we know more.''